RESUMEN
A technique for the creation of free-standing cryogenic targets for laser-driven ion acceleration is presented, which allows us to create solid state targets consisting of initially gaseous materials. In particular, the use of deuterium and the methods for its preparation as a target material for laser-driven ion acceleration are discussed. Moving in the phase diagram through the liquid phase leads to the substance covering an aperture on a cooled copper frame where it is solidified through further cooling. An account of characterization techniques for target thickness is given, with a focus on deducing thickness values from distance values delivered by chromatic confocal sensors.
RESUMEN
We used time-resolved shadowgraphy to characterize the pre-plasma formation in solid-target interaction experiments with micrometer-scale accuracy. We performed quantitative measurements of the plasma density for amplified spontaneous emission (ASE) levels ranging from 2 · 10(-7) to 10(-10) backed with 2-dimensional hydrodynamic simulations. We find that ASE levels above 10(-9) are able to create a significant pre-plasma plume that features a plasma canal driving a self-focusing of the laser beam. For ASE levels of 10(-10), no ASE pre-plasma could be detected.